Mercury Chloride-Induced Glucose Intolerance in Rats: Role of Oxidative Stress

Mercury is recognized as a hazardous environmental and industrial pollutant; however it is commercially important in many industries/applications. This has therefore led to an increase in occupational and environmental exposures in many parts of the world. The present study evaluated the impact of mercury chloride on glucose homeostasis and the possible involvement of oxidative stress. In addition, the potential protective effects of Alpha Lipoic Acid (ALA), a naturally occurring and unique antioxidant on mercury chloride toxicity were investigated. Thirty rats were randomly divided into five equal groups of six animals: Group 1 (control) received 0.5 mL distilled water; Group 2 (ALA) received 100 ug/kg of ALA; Group 3 (LDM) and Group 4 (HDM) received 250 and 500 ug/kg body weight of HgCl2, respectively; and Group 5 (HDMALA) received 500 ug/kg body weight of HgCl2 simultaneously with 100 ug/kg of ALA. Both HgCl2 and ALA were administered orally for 14 consecutive days. The fasting blood glucose was measured and all groups were subjected to Oral Glucose Tolerance Test (OGTT). In addition, the activities of reduced glutathione, superoxide dismutase, catalase as well as the level of lipid peroxidation were estimated. The results showed significant adverse changes in glucose tolerance and oxidative indices in rats exposed to mercury chloride. However, treatment with ALA attenuated all mercury triggered changes. This study clearly demonstrates the induction of glucose intolerance by mercury chloride and suggests the involvement of oxidative stress as an important regulator of glucose homeostasis during mercury chloride exposure.